alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed TA401 Related Domain in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".cryptoanalyzetech.com"; endswith; fast_pattern; reference:url,github.com/Insikt-Group/Research/blob/master/BlueCharlie%2C%20Previously%20Tracked%20as%20TAG-53%2C%20Continues%20to%20Deploy%20New%20Infrastructure%20in%202023/BlueCharlie%2C%20Previously%20Tracked%20as%20TAG-53%2C%20Continues%20to%20Deploy%20New%20Infrastructure%20in%202023.csv; classtype:trojan-activity; sid:2047125; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_07_13, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag TA401, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_08_09, former_sid 2854805, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)